We have updated our json_dto library to version 0.2. The significant changes are:

Custom read_json_value/write_json_value for user types now can be defined in the same namespace with user types (this allows to do custom serialization/deserialization for template types).

The format of read_json_value has been changed. Now it is:

    template < typename DTO >
    void
    read_json_value(
       DTO & v,
       const rapidjson::Value & object );

Support for std::experimental::optional and std::optional from C++17 is added.